As a beginner and an older athlete, I have come to realize that to make sure I get the most out of my training, I have to make sure that I train with the right partner for what I am trying to achieve. It has taken me a while to realize this, but drilling or rolling may require a different partner for what you want. We all know that rolling with higher belts can be beneficial, dealing with their technical superiority makes you think. But there also other things to consider, depending on your current focus. That is why choosing the right partner for your bjj training is an important decision.
Are you looking to focus on techniques that would deal with someone who is strong. You have the option to work with someone bigger than you so you have to deal with the increase in strength in a more technical way. As out muscling them would not be an option, so relying on improving techniques is the only way to go. Or, do you want to improve your speed so someone strong can’t really settle on you. So you may want to work with someone slightly smaller, or in my case younger who has more of a movement game. This can improve your cardio and reactions.
Sometimes, too, it is worth looking at body sizes. I fight at middleweight and I am 6 feet 3 inches tall. I have fought guys a couple of inches taller and I have fought guys much shorter than me. It is realistic to assume that not all my opponents will be the same size as my, so drilling and sparring with different sizes gives you the opportunity to deal with the issues that these differences can pose.
There may also be new techniques that you want to focus on. So after the drilling, you want to work on it in sparring. It may be beneficial starting with newer guys. They would have less game to react with, but will still give you a reaction to deal with. Then moving up experience level with the technique, gives you more to deal with, especially with the guys that have experienced the technique before and have a standard defence or response.
Working with the bigger guys can also be of benefit in a couple of ways. It can help you get comfortable in horrible situations. If you can allow yourself to relax when you are under the side control of a larger partner, someone your own weight will feel easier. The reverse also applies. Trying to maintain top control on someone bigger guy is a challenge in itself.
Finally and probably most obviously, working with the guys who have specialisms have great benefits. I got beat in a competition with a footlock. I came away and sparred with the guy at the club who was hitting footlocks on everyone. This made my practical footlock defense a lot better and made me very aware of the risk. Same would go with the guys that like playing an inverted game, or like playing from the guard. Knowing who these guys are can be a great benefit.
I am not suggesting you do this all the time, we all have people we like to drill or train with for many different reasons. Enjoying your rolling in this way is important. The other side of this is purposeful training, to work on specifics. To get the most out of this, having an appropriate partner is an important decision.